With the ever growing power electronics industry, inductors have become increasingly important in applications such as power generation, power quality, AC drives, regenerative drives etc. Inductors are often key components in the equipment used and often determine the efficiency and performance of the equipment in question. An especially problematic area has been in applications where the inductor must handle at the same time a fundamental frequency of e.g. 50 Hz while at the same time filter away from the final signal higher frequencies generated by i.e. switch mode power supplies. Similarly, power electronics often give source to harmful harmonic distortions which have become one of the greatest concerns for the power quality industry today.
Conventional inductors are normally produced by either winding wire on a coil former, in air or to an iron (solid, laminated or ferrite) core. The wire is then wound around the core which often has an air gap to control the permeability in order not to saturate the core material. This gives source to magnetic leak flow, energy losses and heating of the surrounding metal. If the coil is wound over the air gaps there will often be considerable fringing losses, resulting in a hot-spot which can be hard to cool. Inductors furthermore usually have standardized coil formers, conductors and core material. This inevitably leads to limitations in design freedom resulting in ineffective and un-optimized inductor designs.
A first step towards an elimination or alleviation of the above problems has emerged during the last decade, with the birth of a new material technology. This new material technology provides greater possibilities to specially adapt; optimize and integrate these types of actuators in consumer products as well as industrial products. The material technology in question is composites of soft magnetic metallic materials with varying amount of binder and filler, named Soft Magnetic Composites, SMC. The forming of these components made of SMC is of great interest, since the demands on high metal packing ratio and design freedom are in conflict with the known manufacturing methods especially from a production cost perspective. A successful forming process will result in an inductive component, which in many ways is superior to conventional ones in terms of lower losses, smaller size, resulting in a more compact integration in the final device/product.
In addition, many problems are still present with inductors depending on the material choices in terms of energy losses, heat and hot-spot problems, annoying sound, caused by high currents at audible frequencies, unnecessary and ineffective material usage, lower efficiency at higher frequencies, and saturation at low flux intensity, etc.
The use of inductors in the industry is ever increasing, and the demands for higher performing inductors increase with the demand. High performing inductors are also relatively expensive. There is thus a need for a new and improved inductor having improved performance with regard to the problems presented above. The enhanced performance of improved inductors should preferably be implemented in a cost effective way.